O-succinylhomoserine is produced by binding of homoserine and a succinyl group of succinyl-CoA in a biosynthetic pathway. Therefore, in the development of a strain producing O-succinylhomoserine with a high yield, production of homoserine and succinyl CoA is important. Of them, succinyl CoA is produced in the TCA cycle, and thus enhancement of the TCA cycle is required for the production of high concentration of succinyl CoA.
Pentose phosphate pathway (PPP) is well known as a major source of NADPH, and biosynthetic pathways of amino acids require a cofactor NADPH. Therefore, to enhance pentose phosphate pathway in the development of amino acid-producing strains, zwf gene encoding glucose 6-phosphate-1-dehydrogenase involved in a first step of the pathway is generally enhanced, and these strains are disclosed in Korean Patent Publication NOs. 2008-0036608 and 2006-0129352.
When expression of zwf gene or activity of an enzyme encoded thereby is attenuated, pentose phosphate pathway is attenuated, leading to a lack of NADPH supply. In this case, NADPH can be partly replenished by overexpression of isocitrate dehydrogenase (icd) and malate dehydrogenase (mae) of the TCA cycle (Appl Microbiol Biotechnol. 2004 64(1); 91-8, Metab Eng. 2004 6(2); 164-74, FEBS Letters 581 2007 3771-6).
The present inventors have studied to develop a strain capable of producing O-succinylhomoserine with high yield and high efficiency, and they developed a strain, in which zwf gene is attenuated and deleted, for the purpose of producing high concentration of succinyl-CoA as a precursor of O-succinylhomoserine in E. coli having O-succinylhomoserine productivity. As a result of culturing, the present inventors found that O-succinylhomoserine concentration was increased, thereby completing the present disclosure.